I didn't know exactly where to post this but I was curious about the deadlift. Before I ask the question I wanted to thank Jim, his program has helped me leaps and bounds, started with a 320 squat, 365 deadlift, 230 bench, 150 press. I now have a 350 squat, 405 dead (haven't really tried anything higher), 180 press, and 270 bench. My whole outlook on lifting has changed and I don't see myself ever not using 531. That aside my question is if I am even doing the deadlift right. I never have any pain in my back from it and I feel it in my glutes and hamstrings. But this 345 beltless looks like I round my lower back a bit. Deadlift happens to be my favorite movement and the one I want to increase the most.

Your form is fine. Just keep strengthening the abs/low back - some people believe not wearing a belt is all you need. For most people, this is not a good plan of attack. The problem of the back rounding is when the back is not held static during the pull. Aka The Candy Cane - or when you look like a dog taking a dump.